@media (min-width: 1200px) {
    html {
        font-size: 20px !important;
    }
}

@media screen and (min-width: 992px) and (max-width: 1199px) {
    html {
        font-size: 16px !important;
    }
}

@media screen and (min-width: 768px) and (max-width: 991px) {
    html {
        font-size: 14px !important;
    }
}

@media only screen and (min-width: 480px) and (max-width: 767px) {
    html {
        font-size: 10px !important;
    }
}

@media only screen and (max-width: 479px) {
    html {
        font-size: 6px !important;
    }
}

@function s($px) {
    $size: 16px;
    @return $px/$size+rem;
}

.hd-nav {
    ul {
        li:nth-child(1) {
            border-bottom: 1px solid #1746E0;
        }

        li:nth-child(1) a {
            color: #1746E0;
        }
    }
}

html {
    overflow-x: hidden;
}

.endPage {

    .logo {
        min-width: 60px;
        display: block;
        width: 20%;
        font-size: s(30px);
        font-weight: 1000;
        color: #1746E0;
        background-color: #fff;
    }

    &::after {
        display: block;
        content: '';
        height: 3px;
        background-color: #ddd;
        float: left;
        width: 100%;
        min-width: 200px;
        position: absolute;
        margin-top: s(-27px);
        z-index: -1;
        // border: 1px solid red;
    }
}


.container {
    .demo {
        .page-title {
            font-size: s(26px);
            color: #888;
        }

        .first-page {
            height: 600px;
            position: relative;

            .welcome {
                $hight: 300px;
                height: $hight;
                position: relative;
                top: 50%;
                margin-top: -1/2*$hight;

                @media screen and (max-width: 768px) {

                    h1 {
                        font-size: s(60px) !important;
                    }



                    p:nth-child(3) {
                        text-align: right;
                        font-size: s(40px) !important;
                    }

                    p:nth-child(2) {
                        font-size: s(40px) !important;
                    }
                }

                h1 {
                    text-align: center;
                    padding: 10px;
                    font-weight: normal;
                    font-size: s(30px);

                    .name {
                        color: #1746E0;
                    }
                }



                p:nth-child(3) {
                    text-align: right;
                    margin-right: 100px;
                    font-size: s(20px);
                }

                p:nth-child(2) {
                    text-indent: 28px;
                    font-size: s(20px);
                }

                .startLearn {
                    display: block;
                    width: 160px;
                    height: 48px;
                    line-height: 48px;
                    text-align: center;
                    font-size: s(22px);
                    font-weight: 1000;
                    box-sizing: border-box;
                    border-radius: 3px;
                    background-color: #1746E0;
                    color: #fff;
                    text-decoration: none;
                    position: relative;
                    left: 50%;
                    margin-left: -80px;

                }
            }

            img {
                $hight: 300px;
                height: $hight;
                position: relative;
                top: 50%;
                margin-top: -1/2*$hight;
                display: block;

                @media screen and (max-width: 768px) {
                    display: none;
                }

            }

        }

        .second-page {
            height: 666px;

            @media screen and (min-width: 768px) and(max-width: 991px) {

                .popular-courses:last-child {
                    padding: 50px 0 !important;
                    // background-color: red;
                    margin: 0 29.16666666%;

                    p {
                        font-size: s(5px);
                    }
                }
            }

            @media screen and (max-width: 767px) {
                .popular-courses {
                    // background-color: red;
                    margin: 0 25% !important;
                    padding: 0 !important;

                    h3 {
                        padding: 5px 0 !important;
                    }
                }

            }

            .popular-courses {
                padding: 123px 0;
                // background-color: green;
                text-align: center;
                margin: 0 4.16666666%;


                img {
                    display: block;
                    background-color: #fff;
                    border-radius: 50% 50%;
                    width: 150px;
                    position: relative;
                    left: 50%;
                    margin-left: -75px;
                    box-shadow: 0 2px 3px #ddd;
                }

                .introduce {
                    display: inline-block;

                    .title {
                        padding: 20px 0;
                        font-size: s(18px);
                    }

                    p {
                        font-size: s(8px);
                    }
                }
            }
        }

        .third-page {
            height: 666px;

            .zsk {
                height: 600px;
                position: relative;
                background-color: #E8F0F7;

                @media screen and (max-width: 991px) {

                    .zsk-content {
                        margin: -100px 4.13333333% 0 4.13333333% !important;
                    }

                    .robot-shadow {
                        display: none;
                    }

                    .imge {
                        display: none;
                    }
                }

                @media screen and (max-width: 767px) {

                    .zsk-content {
                        top: 0 !important;
                        margin-top: 50px !important;
                    }

                    .robot-shadow {
                        display: none;

                    }

                    .imge {
                        display: none;
                    }

                }

                .zsk-content {
                    height: 200px;
                    position: relative;
                    top: 50%;
                    margin-top: -100px;
                    object-fit: cover;
                }

                .robot-shadow {
                    position: absolute;
                    bottom: 0;
                    border-radius: 50% 50%;
                    height: 50px;
                    background-color: #2d9dff;
                    box-shadow: 0 0 80px 60px #36abff;
                    transform: rotateX(83deg);

                }

                .imge {
                    position: relative;
                    top: 50%;
                    margin: 0 4.13333333%;
                    margin-top: -200px;
                }
            }
        }

        .fourth-page {
            height: 666px;

            @media screen and (max-width: 991px) {
                & {
                    height: 300px;
                }
            }

            .gy-content {
                margin-top: 120px;
                margin-bottom: 80px;
                height: 600px;
                position: relative;

                @media screen and (max-width: 991px) {
                    img {
                        display: none;
                    }
                }

                @media screen and (max-width: 767px) {
                    & {
                        margin-top: 50px;
                    }

                    img {
                        display: none;
                    }

                }

                .gy {
                    height: 300px;

                    p {
                        font-size: s(16px);
                        color: #888;
                        margin: 25px 0;
                    }
                }
            }
        }
    }
}